# SPDX-FileCopyrightText: Copyright (c) 2022-2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import copy
import functools
import json
import os
import sys
import time
from collections import defaultdict
from pathlib import Path
from typing import List, Optional

import numpy as np
import safetensors
import torch
import torch.nn as nn
from tqdm import tqdm
from transformers import AutoConfig, AutoModelForCausalLM, AutoTokenizer
from transformers.models.llama.modeling_llama import LlamaDecoderLayer
from transformers.pytorch_utils import Conv1D

from ..._utils import pad_vocab_size, release_gc, str_dtype_to_torch
from ...logger import logger
from ...quantization import QuantAlgo
from ..convert_utils import (iterate_shard_files, load_calib_dataset,
                             load_state_dict, retrieved_layer_index_from_name)
from ..modeling_utils import PretrainedConfig
from .config import LLaMAConfig


def generate_int8(weights, act_range, is_qkv=False, multi_query_mode=False):
    """
     This function has two purposes:
      - compute quantized weights, scaled either per-tensor or per-column
      - compute scaling factors

      Depending on the GEMM API (CUTLASS/CUBLAS) the required scaling factors differ.
      CUTLASS uses two sets of scaling factors. One for the activation X, one for the weight W.
      CUBLAS only has one (we can't do per-row scaling). So we must provide pre-multiplied scaling factor.

      Here is the list of what we need (T means per-tensor, C per-column):
        - scale_x_orig_quant puts fp activation into the quantized range (i.e. [-128, 127], for int8). Used before the GEMM. (T)
        - scale_y_quant_orig puts quantized activation into the fp range. Used if the GEMM outputs int8. (T)
        - scale_w_quant_orig puts weights from quant range to fp range (used with CUTLASS) (T, C)
        - scale_y_accum_quant puts the GEMM result (XW) from accumulation range (int32)
          to quant range (int8) (used for CUBLAS) (T, C)

      Note that we don't do anything special about row-parallel GEMM. Theoretically, we could have per-GPU scaling factors too,
      but then the model would change depending on the number of GPUs used.

      For QKV projection, the behavior is special. Even if we have a single matrix to perform QKV projection, we consider it
      as three different matrices: Q, K, and V. So per-tensor actually means one scaling factor for each Q, K and V.
      For our GEMM implementation to respect this behavior, we use per-column mode and replicate values along columns.
    """

    # compute weight scaling factors for fp->int8 and int8->fp
    if is_qkv and not multi_query_mode:
        scale_w_orig_quant_t = 127. / act_range["w"].reshape(3, -1).max(
            dim=-1, keepdims=True)[0]
        scale_w_orig_quant_c = 127. / act_range["w"].reshape(3, -1)
    elif is_qkv and multi_query_mode:
        hidden_dim = weights.shape[0]
        local_dim = act_range["w"].shape[0]
        kv_dim = (local_dim - hidden_dim) // 2
        scale_w_q = act_range["w"][0:hidden_dim]
        scale_w_k = act_range["w"][hidden_dim:hidden_dim + kv_dim]
        scale_w_v = act_range["w"][-kv_dim:]

        scale_w_qkv_t = torch.concat([
            scale_w_q.max(dim=0, keepdim=True)[0],
            scale_w_k.max(dim=0, keepdim=True)[0],
            scale_w_v.max(dim=0, keepdim=True)[0]
        ])

        scale_w_orig_quant_t = 127. / scale_w_qkv_t
        scale_w_orig_quant_c = 127. / act_range["w"]
    else:
        scale_w_orig_quant_t = 127. / act_range["w"].max()
        scale_w_orig_quant_c = 127. / act_range["w"]
    scale_w_quant_orig_t = 1.0 / scale_w_orig_quant_t
    scale_w_quant_orig_c = 1.0 / scale_w_orig_quant_c

    scale_w_orig_quant_c = scale_w_orig_quant_c.to(torch.float32)
    scale_w_orig_quant_t = scale_w_orig_quant_t.to(torch.float32)

    # compute the rest of needed scaling factors
    scale_x_orig_quant_t = 127. / act_range["x"].max()
    scale_y_orig_quant_t = 127. / act_range["y"].max()
    scale_y_quant_orig_t = act_range["y"].max() / 127.
    scale_y_accum_quant_t = scale_y_orig_quant_t / (scale_x_orig_quant_t *
                                                    scale_w_orig_quant_t)
    scale_y_accum_quant_c = scale_y_orig_quant_t / (scale_x_orig_quant_t *
                                                    scale_w_orig_quant_c)
    if is_qkv and not multi_query_mode:
        scale_y_accum_quant_t = torch.broadcast_to(scale_y_accum_quant_t,
                                                   scale_w_orig_quant_c.shape)
        scale_w_quant_orig_t = torch.broadcast_to(scale_w_quant_orig_t,
                                                  scale_w_orig_quant_c.shape)
    if is_qkv and multi_query_mode:
        scale_q_y_accum_t = torch.broadcast_to(scale_y_accum_quant_t[0],
                                               scale_w_q.shape)
        scale_k_y_accum_t = torch.broadcast_to(scale_y_accum_quant_t[1],
                                               scale_w_k.shape)
        scale_v_y_accum_t = torch.broadcast_to(scale_y_accum_quant_t[2],
                                               scale_w_v.shape)
        scale_y_accum_quant_t = torch.concat(
            [scale_q_y_accum_t, scale_k_y_accum_t, scale_v_y_accum_t])
        scale_w_quant_orig_t = torch.concat([
            torch.broadcast_to(scale_w_quant_orig_t[0], scale_w_q.shape),
            torch.broadcast_to(scale_w_quant_orig_t[1], scale_w_k.shape),
            torch.broadcast_to(scale_w_quant_orig_t[2], scale_w_v.shape)
        ])

    to_i8 = lambda x: x.round().clip(-127, 127).to(torch.int8)

    if is_qkv and multi_query_mode:
        weight_int8 = to_i8(weights / scale_w_quant_orig_t)
    else:
        weight_int8 = to_i8(weights * scale_w_orig_quant_t)
    return {
        "weight.int8": weight_int8,
        "weight.int8.col": to_i8(weights * scale_w_orig_quant_c),
        "scale_x_orig_quant": scale_x_orig_quant_t.to(torch.float32),
        "scale_w_quant_orig": scale_w_quant_orig_t.to(torch.float32),
        "scale_w_quant_orig.col": scale_w_quant_orig_c.to(torch.float32),
        "scale_y_accum_quant": scale_y_accum_quant_t.to(torch.float32),
        "scale_y_accum_quant.col": scale_y_accum_quant_c.to(torch.float32),
        "scale_y_quant_orig": scale_y_quant_orig_t.to(torch.float32),
    }


@torch.no_grad()
def apply_smoothing(scales,
                    gemm_weights,
                    layernorm_weights=None,
                    layernorm_bias=None,
                    dtype=torch.float32,
                    layernorm_1p=False):
    if not isinstance(gemm_weights, list):
        gemm_weights = [gemm_weights]

    if layernorm_weights is not None:
        assert layernorm_weights.numel() == scales.numel()
        layernorm_weights.div_(scales).to(dtype)
    if layernorm_bias is not None:
        assert layernorm_bias.numel() == scales.numel()
        layernorm_bias.div_(scales).to(dtype)
    if layernorm_1p:
        layernorm_weights += (1 / scales) - 1

    for gemm in gemm_weights:
        gemm.mul_(scales.view(1, -1)).to(dtype)


@torch.no_grad()
def smooth_gemm(gemm_weights,
                act_scales,
                layernorm_weights=None,
                layernorm_bias=None,
                alpha=0.5,
                weight_scales=None):
    if not isinstance(gemm_weights, list):
        gemm_weights = [gemm_weights]
    orig_dtype = gemm_weights[0].dtype

    for gemm in gemm_weights:
        # gemm_weights are expected to be transposed
        assert gemm.shape[1] == act_scales.numel()

    if weight_scales is None:
        weight_scales = torch.cat(
            [gemm.abs().max(dim=0, keepdim=True)[0] for gemm in gemm_weights],
            dim=0)
        weight_scales = weight_scales.max(dim=0)[0]
    weight_scales.to(float).clamp(min=1e-5)
    scales = (act_scales.to(gemm_weights[0].device).to(float).pow(alpha) /
              weight_scales.pow(1 - alpha)).clamp(min=1e-5)

    apply_smoothing(scales, gemm_weights, layernorm_weights, layernorm_bias,
                    orig_dtype)

    return scales


@torch.no_grad()
def smooth_gemm_fc1_gate(fc1_weights,
                         gate_weights,
                         act_scales,
                         layernorm_weights=None,
                         layernorm_bias=None,
                         alpha=0.5,
                         weight_scales=None):
    gemm_weights = []
    if not isinstance(fc1_weights, list):
        fc1_weights = [fc1_weights]
    if not isinstance(gate_weights, list):
        gate_weights = [gate_weights]

    for i in range(len(fc1_weights)):
        gemm_weight = torch.cat([fc1_weights[i], gate_weights[i]], dim=0)
        gemm_weights.append(gemm_weight)

    orig_dtype = gemm_weights[0].dtype

    for gemm in gemm_weights:
        # gemm_weights are expected to be transposed
        assert gemm.shape[1] == act_scales.numel()

    if weight_scales is None:
        weight_scales = torch.cat(
            [gemm.abs().max(dim=0, keepdim=True)[0] for gemm in gemm_weights],
            dim=0)
        weight_scales = weight_scales.max(dim=0)[0]
    weight_scales.to(float).clamp(min=1e-5)
    scales = (act_scales.to(gemm_weights[0].device).to(float).pow(alpha) /
              weight_scales.pow(1 - alpha)).clamp(min=1e-5)

    apply_smoothing(scales, fc1_weights + gate_weights, layernorm_weights,
                    layernorm_bias, orig_dtype)

    return scales


@torch.no_grad()
def smooth_llama_model(model, scales, alpha, llama_qkv_para, llama_smoother):
    # Smooth the activation and weights with smoother = $\diag{s}$
    for name, module in model.named_modules():
        if not isinstance(
                module,
                LlamaDecoderLayer) and not module.__class__.__name__ in [
                    "InternLMDecoderLayer", "MistralDecoderLayer"
                ]:
            continue
        # qkv_proj
        layer_name_q = name + ".self_attn.q_proj"
        layer_name_k = name + ".self_attn.k_proj"
        layer_name_v = name + ".self_attn.v_proj"
        layer_name_qkv = name + ".self_attn.qkv_proj"

        weight = torch.cat([
            module.self_attn.q_proj.weight, module.self_attn.k_proj.weight,
            module.self_attn.v_proj.weight
        ],
                           dim=0)

        smoother = smooth_gemm(weight, scales[layer_name_q]["x"],
                               module.input_layernorm.weight, None, alpha)

        scales[layer_name_qkv]["x"] = scales[layer_name_q]["x"] / smoother
        scales[layer_name_qkv]["w"] = weight.abs().max(dim=1)[0]
        scales[layer_name_qkv]["y"] = torch.cat([
            scales[layer_name_q]["y"], scales[layer_name_k]["y"],
            scales[layer_name_v]["y"]
        ],
                                                dim=0)

        # see transpose_weights function
        llama_qkv_para[layer_name_qkv] = weight.transpose(0, 1)

        # =================================================================
        layer_name = name + ".self_attn.o_proj"
        smoother = smooth_gemm(module.self_attn.o_proj.weight,
                               scales[layer_name]["x"], None, None, alpha)
        llama_smoother[layer_name] = smoother.float()

        scales[layer_name]["x"] = scales[layer_name]["x"] / smoother
        scales[layer_name]["w"] = module.self_attn.o_proj.weight.abs().max(
            dim=1)[0]

        # ==================================================================
        fc1_layer_name = name + ".mlp.gate_proj"
        gate_layer_name = name + ".mlp.up_proj"

        smoother = smooth_gemm_fc1_gate(module.mlp.gate_proj.weight,
                                        module.mlp.up_proj.weight,
                                        scales[fc1_layer_name]["x"],
                                        module.post_attention_layernorm.weight,
                                        None, alpha)

        scales[fc1_layer_name]["x"] = scales[fc1_layer_name]["x"] / smoother
        scales[fc1_layer_name]["w"] = module.mlp.gate_proj.weight.abs().max(
            dim=1)[0]

        scales[gate_layer_name]["x"] = scales[gate_layer_name]["x"] / smoother
        scales[gate_layer_name]["w"] = module.mlp.up_proj.weight.abs().max(
            dim=1)[0]

        # ==================================================================
        layer_name = name + ".mlp.down_proj"
        smoother = smooth_gemm(module.mlp.down_proj.weight,
                               scales[layer_name]["x"], None, None, alpha)
        llama_smoother[layer_name] = smoother.float()
        scales[layer_name]["x"] = scales[layer_name]["x"] / smoother
        scales[layer_name]["w"] = module.mlp.down_proj.weight.abs().max(
            dim=1)[0]

        # ==================================================================
        if hasattr(module, 'residual_mlp'):
            fc1_layer_name = name + ".residual_mlp.w1"
            gate_layer_name = name + ".residual_mlp.w3"

            smoother = smooth_gemm_fc1_gate(module.residual_mlp.w1.weight,
                                            module.residual_mlp.w3.weight,
                                            scales[fc1_layer_name]["x"],
                                            module.residual_layernorm.weight,
                                            None, alpha)

            scales[fc1_layer_name]["x"] = scales[fc1_layer_name]["x"] / smoother
            scales[fc1_layer_name]["w"] = module.residual_mlp.w1.weight.abs(
            ).max(dim=1)[0]

            scales[gate_layer_name][
                "x"] = scales[gate_layer_name]["x"] / smoother
            scales[gate_layer_name]["w"] = module.residual_mlp.w3.weight.abs(
            ).max(dim=1)[0]

            # ==================================================================
            layer_name = name + ".residual_mlp.w2"
            smoother = smooth_gemm(module.residual_mlp.w2.weight,
                                   scales[layer_name]["x"], None, None, alpha)
            llama_smoother[layer_name] = smoother.float()
            scales[layer_name]["x"] = scales[layer_name]["x"] / smoother
            scales[layer_name]["w"] = module.residual_mlp.w2.weight.abs().max(
                dim=1)[0]


@torch.no_grad()
def capture_activation_range(model,
                             tokenizer,
                             dataset,
                             num_samples=512,
                             seq_len=512):
    model.eval()
    device = next(model.parameters()).device
    act_scales = defaultdict(lambda: {"x": None, "y": None, "w": None})

    tokenizer.pad_token = tokenizer.eos_token

    def stat_tensor(name, tensor, act_scales, key):
        hidden_dim = tensor.shape[-1]
        tensor = tensor.view(-1, hidden_dim).abs().detach()
        comming_max = torch.max(tensor, dim=0)[0].float()

        if act_scales[name][key] is None:
            act_scales[name][key] = comming_max
        else:
            act_scales[name][key] = torch.max(act_scales[name][key],
                                              comming_max)

    def stat_input_hook(m, x, y, name):
        if isinstance(x, tuple):
            x = x[0]
        stat_tensor(name, x, act_scales, "x")
        stat_tensor(name, y, act_scales, "y")

        if act_scales[name]["w"] is None:
            act_scales[name]["w"] = m.weight.abs().clip(1e-8,
                                                        None).max(dim=1)[0]

    hooks = []
    for name, m in model.named_modules():
        if isinstance(m, nn.Linear) or isinstance(m, Conv1D):
            hooks.append(
                m.register_forward_hook(
                    functools.partial(stat_input_hook, name=name)))

    for i in tqdm(range(num_samples), desc="calibrating model"):
        datapoint = dataset[i:i + 1]
        line = copy.copy(datapoint)
        line[0] = line[0] + ' TL;DR: '
        line[0] = line[0].strip()
        line[0] = line[0].replace(" n't", "n't")
        input_ids = tokenizer(line,
                              return_tensors="pt",
                              max_length=seq_len,
                              padding=True,
                              truncation=True).input_ids.to(device)
        model(input_ids)
    for h in hooks:
        h.remove()
    return act_scales


def split(v, tp_size, idx, dim=0):
    if tp_size == 1:
        return v
    if len(v.shape) == 1:
        return torch.chunk(v, tp_size)[idx].contiguous()
    else:
        return torch.chunk(v, tp_size, dim=dim)[idx]


def split_qkv_tp(v, n_head, n_hidden, tensor_parallel, rank):
    """
    Splits the QKV matrix according to tensor parallelism
    """
    v = v.reshape(3, n_hidden, n_hidden)
    split_v = split(v, tensor_parallel, rank, dim=1)
    split_v = split_v.reshape(3 * (n_hidden // tensor_parallel), n_hidden)
    return split_v


def split_qkv_bias_tp(v, n_head, n_hidden, tensor_parallel, rank):
    """
    Splits the QKV bias according to tensor parallelism
    """
    v = v.reshape(3, n_hidden)
    split_v = split(v, tensor_parallel, rank, dim=1)
    split_v = split_v.reshape(3 * (n_hidden // tensor_parallel))
    return split_v


def split_matrix_tp(v, tensor_parallel, rank, dim):
    return split(v, tensor_parallel, rank, dim=dim)


def get_weight(config, prefix, dtype):
    if config[prefix + '.weight'].dtype != dtype:
        config[prefix + '.weight'].data = config[prefix + '.weight'].to(dtype)
    return config[prefix + '.weight'].detach()


def get_bias(config, prefix, dtype):
    if config[prefix + '.bias'].dtype != dtype:
        config[prefix + '.bias'].data = config[prefix + '.bias'].to(dtype)
    return config[prefix + '.bias'].detach()


def get_weight_and_bias(config, prefix, dtype):
    return get_weight(config, prefix, dtype), get_bias(config, prefix, dtype)


def get_tllm_linear_weight(weight,
                           prefix,
                           bias=None,
                           use_weight_only=False,
                           plugin_weight_only_quant_type=torch.int8,
                           dtype='float32',
                           use_gemm_woq_plugin=True,
                           postfix='weight',
                           quant_scale_name=None):
    results = {}
    if use_weight_only:
        if weight.dim() > 2:
            v = weight.transpose(1, 2).contiguous()
        else:
            v = weight.t().contiguous()
        processed_torch_weights, torch_weight_scales = \
            torch.ops.trtllm.symmetric_quantize_last_axis_of_batched_matrix(
                v.cpu(), plugin_weight_only_quant_type)
        if not use_gemm_woq_plugin:
            results[prefix + postfix] = v.to(dtype)
        else:
            results[prefix + postfix] = processed_torch_weights
        if quant_scale_name is not None:
            results[quant_scale_name] = torch_weight_scales
        else:
            results[prefix + 'per_channel_scale'] = torch_weight_scales
    else:
        results[prefix + postfix] = weight

    if bias is not None:
        results[prefix + 'bias'] = bias

    return results


def dup_kv_weight(v, num_head, tp_size):
    assert tp_size % num_head == 0
    reps = tp_size // num_head
    head_size = v.shape[0] // num_head
    v = v.reshape(num_head, head_size,
                  -1)[:, None, :, :].expand(num_head, reps, head_size,
                                            v.shape[1])
    return v.reshape(num_head * reps * head_size, -1).clone().detach()


def get_tllm_linear_sq_weight(vals,
                              prefix,
                              shape,
                              tensor_parallel,
                              is_qkv=False,
                              per_token=False,
                              per_channel=False,
                              last_prefix=None,
                              bias=None,
                              smoother_value=None,
                              smoother_shape=None,
                              rank=0,
                              cat_dim=0,
                              multi_query_mode=False):
    results = {}

    def multi_query_split(data, local_dim, head_size, tp_size, cur_rank):
        q, k, v = torch.split(data, [local_dim, head_size, head_size], dim=-1)
        q_split = torch.chunk(q, tp_size, dim=-1)
        k_split = torch.chunk(k, tp_size, dim=-1)
        v_split = torch.chunk(v, tp_size, dim=-1)
        return [
            torch.concat((q_split[ii], k_split[ii], v_split[ii]), axis=-1)
            for ii in range(tp_size)
        ][cur_rank]

    col_shape = shape if (is_qkv or per_channel) else [1, 1]

    if per_token:
        if per_channel:
            original_weights = torch.Tensor(vals["weight.int8.col"]).cuda()
        else:
            original_weights = torch.Tensor(vals["weight.int8"]).cuda()
        local_dim = original_weights.shape[0]
        head_size = (original_weights.shape[1] - local_dim) // 2

        if multi_query_mode:
            cur_weights = multi_query_split(original_weights, local_dim,
                                            head_size, tensor_parallel, rank)
        else:
            cur_weights = torch.chunk(original_weights,
                                      tensor_parallel,
                                      dim=cat_dim)[rank]
        if is_qkv:
            hidden_dim = cur_weights.shape[0]
            cur_weights = cur_weights.reshape(hidden_dim, -1)
        results[prefix + 'weight'] = cur_weights.t().contiguous()
        if smoother_value is None:
            results[last_prefix] = torch.Tensor([1.0]).to(torch.float32).cuda()

        if per_channel:
            cur_per_channel_value = vals["scale_w_quant_orig.col"]
            if smoother_value is None:
                if multi_query_mode:
                    cur_per_channel_value = multi_query_split(
                        vals["scale_w_quant_orig.col"], local_dim, head_size,
                        tensor_parallel, rank)
                else:
                    cur_per_channel_value = torch.chunk(
                        vals["scale_w_quant_orig.col"],
                        tensor_parallel,
                        dim=cat_dim)[rank]
        else:
            cur_per_channel_value = vals["scale_w_quant_orig"]
            if is_qkv:
                if multi_query_mode:
                    cur_per_channel_value = multi_query_split(
                        vals["scale_w_quant_orig"], local_dim, head_size,
                        tensor_parallel, rank)
                else:
                    cur_per_channel_value = torch.chunk(
                        vals["scale_w_quant_orig"],
                        tensor_parallel,
                        dim=cat_dim)[rank]

        results[prefix + 'per_channel_scale'] = cur_per_channel_value.reshape(
            col_shape).contiguous()
    else:
        if per_channel:
            original_weights = torch.Tensor(vals["weight.int8.col"]).cuda()
        else:
            original_weights = torch.Tensor(vals["weight.int8"]).cuda()
        local_dim = original_weights.shape[0]
        head_size = (original_weights.shape[1] - local_dim) // 2

        if multi_query_mode:
            cur_weights = multi_query_split(original_weights, local_dim,
                                            head_size, tensor_parallel, rank)
        else:
            cur_weights = torch.chunk(original_weights,
                                      tensor_parallel,
                                      dim=cat_dim)[rank]
        if is_qkv:
            hidden_dim = cur_weights.shape[0]
            cur_weights = cur_weights.reshape(hidden_dim, -1)
        results[prefix + 'weight'] = cur_weights.t().contiguous()

        if per_channel:
            cur_per_channel_value = vals["scale_y_accum_quant.col"]
            if smoother_value is None:
                if multi_query_mode:
                    cur_per_channel_value = multi_query_split(
                        vals["scale_y_accum_quant.col"], local_dim, head_size,
                        tensor_parallel, rank)
                else:
                    cur_per_channel_value = torch.chunk(
                        vals["scale_y_accum_quant.col"],
                        tensor_parallel,
                        dim=cat_dim)[rank]
        else:
            cur_per_channel_value = vals["scale_y_accum_quant"]
            # QKV is always per_channel
            if is_qkv:
                if multi_query_mode:
                    cur_per_channel_value = multi_query_split(
                        vals["scale_y_accum_quant"], local_dim, head_size,
                        tensor_parallel, rank)
                else:
                    cur_per_channel_value = torch.chunk(
                        vals["scale_y_accum_quant"],
                        tensor_parallel,
                        dim=cat_dim)[rank]

        results[prefix +
                'per_channel_scale'] = torch.Tensor(cur_per_channel_value).to(
                    torch.float32).reshape(col_shape).contiguous().cuda()
        results[prefix + 'act_scale'] = torch.Tensor([[
            vals['scale_y_quant_orig']
        ]]).to(torch.float32).contiguous().cuda()
        results[last_prefix] = torch.Tensor([vals['scale_x_orig_quant']]).to(
            torch.float32).contiguous().cuda()

    if smoother_value is not None:
        cur_smoother_value = torch.chunk(smoother_value,
                                         tensor_parallel,
                                         dim=cat_dim)[rank]
        results[prefix + 'smoother'] = cur_smoother_value.reshape(
            smoother_shape).contiguous().to(torch.float32)

    if bias is not None:
        results[prefix + 'bias'] = bias

    return results


def load_hf_llama(model_dir: str, load_model_on_cpu: bool = False):
    if "vila" in model_dir:
        sys.path.append(model_dir + "/../VILA")
        from llava.model import LlavaLlamaConfig, LlavaLlamaModel  # noqa
        from transformers import AutoModel
        model = AutoModel.from_pretrained(
            model_dir,
            device_map='auto',
            trust_remote_code=True,
        )
        return model.llm

    hf_config = AutoConfig.from_pretrained(model_dir, trust_remote_code=True)
    model_cls = AutoModelForCausalLM
    if hf_config.model_type == "llava":
        from transformers import LlavaForConditionalGeneration
        model_cls = LlavaForConditionalGeneration
    model = model_cls.from_pretrained(
        model_dir,
        device_map='auto' if not load_model_on_cpu else 'cpu',
        torch_dtype='auto',
        trust_remote_code=True,
    )
    if hf_config.model_type == "llava":
        model = model.language_model
    return model


def load_weights_from_hf_model(hf_model,
                               config: LLaMAConfig,
                               act_range: Optional[dict] = None,
                               qkv_para: Optional[dict] = None,
                               smoother: Optional[dict] = None):
    quant_algo = config.quantization.quant_algo
    use_weight_only = quant_algo in [QuantAlgo.W8A16, QuantAlgo.W4A16]
    if quant_algo == QuantAlgo.W8A16:
        plugin_weight_only_quant_type = torch.int8
    elif quant_algo == QuantAlgo.W4A16:
        plugin_weight_only_quant_type = torch.quint4x2
    else:
        plugin_weight_only_quant_type = None
    use_gemm_woq_plugin = (not config.disable_weight_only_quant_plugin)

    use_smooth_quant = config.quantization.use_plugin_sq
    per_channel = use_smooth_quant and 'PER_CHANNEL' in quant_algo
    per_token = use_smooth_quant and 'PER_TOKEN' in quant_algo
    int8_kv_cache = config.quantization.kv_cache_quant_algo == QuantAlgo.INT8
    if use_smooth_quant or int8_kv_cache:
        assert act_range is not None
        assert qkv_para is not None
        assert smoother is not None

    weights = {}
    tik = time.time()
    model_params = dict(hf_model.named_parameters())
    dtype = getattr(torch, config.dtype)

    mapping = config.mapping
    moe_config = config.moe
    mha_mode = (config.num_key_value_heads == config.num_attention_heads)
    layers_range = config.mapping.pp_layers(config.num_hidden_layers)

    def convert_layer(l):
        prefix = f'model.layers.{l}.'
        tllm_prex = f'transformer.layers.{l - layers_range[0]}.'
        q_weight = get_weight(model_params, prefix + 'self_attn.q_proj', dtype)
        k_weight = get_weight(model_params, prefix + 'self_attn.k_proj', dtype)
        v_weight = get_weight(model_params, prefix + 'self_attn.v_proj', dtype)

        if not mha_mode:
            if config.num_key_value_heads < mapping.tp_size:
                # duplicate the KV heads up to tensor_parallel
                k_weight = dup_kv_weight(k_weight, config.num_key_value_heads,
                                         mapping.tp_size)
                v_weight = dup_kv_weight(v_weight, config.num_key_value_heads,
                                         mapping.tp_size)
            assert (k_weight.shape[0] %
                    (mapping.tp_size * config.head_size)) == 0
            assert (v_weight.shape[0] %
                    (mapping.tp_size * config.head_size)) == 0

            wq = split(q_weight, mapping.tp_size, mapping.tp_rank)
            wk = split(k_weight, mapping.tp_size, mapping.tp_rank)
            wv = split(v_weight, mapping.tp_size, mapping.tp_rank)

            split_v = torch.concat((wq, wk, wv))

        else:
            qkv_weight = torch.cat([q_weight, k_weight, v_weight], dim=0)

            split_v = split_qkv_tp(qkv_weight, config.num_attention_heads,
                                   config.hidden_size, mapping.tp_size,
                                   mapping.tp_rank)

        if prefix + 'self_attn.q_proj.bias' in model_params:
            # only used in Internlm 7B models
            q_bias = get_bias(model_params, prefix + 'self_attn.q_proj', dtype)
            k_bias = get_bias(model_params, prefix + 'self_attn.k_proj', dtype)
            v_bias = get_bias(model_params, prefix + 'self_attn.v_proj', dtype)
            qkv_bias = torch.cat((q_bias, k_bias, v_bias))
            split_bias_v = split_qkv_bias_tp(qkv_bias,
                                             config.num_attention_heads,
                                             config.hidden_size,
                                             mapping.tp_size, mapping.tp_rank)
        else:
            split_bias_v = None

        if use_smooth_quant:
            qkv_weight = qkv_para[prefix + 'self_attn.qkv_proj']
            qkv_out_dim = qkv_weight.shape[1]

            if not mha_mode:
                local_dim = qkv_weight.shape[0]
                kv_hidden_size = (qkv_weight.shape[-1] - local_dim) // 2
                qkv_weight = qkv_weight.reshape(local_dim,
                                                local_dim + 2 * kv_hidden_size)
            else:
                qkv_weight = qkv_weight.reshape(config.hidden_size, 3,
                                                config.hidden_size)

            int8_weights = generate_int8(qkv_weight,
                                         act_range.get(prefix +
                                                       'self_attn.qkv_proj'),
                                         is_qkv=True,
                                         multi_query_mode=bool(not mha_mode))

            weights.update(
                get_tllm_linear_sq_weight(int8_weights,
                                          tllm_prex + 'attention.qkv.',
                                          [1, qkv_out_dim // mapping.tp_size],
                                          mapping.tp_size,
                                          is_qkv=True,
                                          bias=split_bias_v,
                                          per_token=per_token,
                                          per_channel=per_channel,
                                          last_prefix=tllm_prex +
                                          'input_layernorm.scale_to_int',
                                          smoother_value=None,
                                          smoother_shape=None,
                                          rank=mapping.tp_rank,
                                          cat_dim=-1,
                                          multi_query_mode=bool(not mha_mode)))
        else:
            weights.update(
                get_tllm_linear_weight(split_v, tllm_prex + 'attention.qkv.',
                                       split_bias_v, use_weight_only,
                                       plugin_weight_only_quant_type, dtype,
                                       use_gemm_woq_plugin))

        if int8_kv_cache:
            qkv_y = torch.cat([
                act_range.get(prefix + 'self_attn.q_proj')["y"],
                act_range.get(prefix + 'self_attn.k_proj')["y"],
                act_range.get(prefix + 'self_attn.v_proj')["y"]
            ],
                              dim=0)

            int8_kv_scales = qkv_y.max() / 127.

            kv_cache_weights = {}

            kv_cache_weights[
                tllm_prex +
                'attention.kv_cache_scaling_factor'] = int8_kv_scales.reshape(
                    [1])

            weights.update(kv_cache_weights)

        attn_dense_weight = get_weight(model_params,
                                       prefix + 'self_attn.o_proj', dtype)
        split_v = split_matrix_tp(attn_dense_weight,
                                  mapping.tp_size,
                                  mapping.tp_rank,
                                  dim=1)

        if prefix + 'self_attn.o_proj.bias' in model_params:
            attn_dense_bias = get_bias(model_params,
                                       prefix + 'self_attn.o_proj', dtype)
        else:
            attn_dense_bias = None
        if use_smooth_quant:
            attn_dense_weight = attn_dense_weight.t()
            int8_weights = generate_int8(
                attn_dense_weight, act_range.get(prefix + 'self_attn.o_proj'))
            weights.update(
                get_tllm_linear_sq_weight(
                    int8_weights,
                    tllm_prex + 'attention.dense.', [1, config.hidden_size],
                    mapping.tp_size,
                    is_qkv=False,
                    bias=attn_dense_bias,
                    per_token=per_token,
                    per_channel=per_channel,
                    last_prefix=tllm_prex +
                    'attention.quantization_scaling_factor',
                    smoother_value=smoother[(prefix + 'self_attn.o_proj')],
                    smoother_shape=[1, config.hidden_size // mapping.tp_size],
                    rank=mapping.tp_rank,
                    cat_dim=0))
        else:
            weights.update(
                get_tllm_linear_weight(split_v, tllm_prex + 'attention.dense.',
                                       attn_dense_bias, use_weight_only,
                                       plugin_weight_only_quant_type, dtype,
                                       use_gemm_woq_plugin))

        if moe_config.has_moe():
            rank_experts = list(range(moe_config.num_experts))
            if moe_config.tp_mode == moe_config.ParallelismMode.EXPERT_PARALLEL:
                rank_experts = mapping.ep_experts(moe_config.num_experts)
            for suffix in ["w1", "w2", "w3"]:
                model_params[f'model.layers.{l}.block_sparse_moe.experts.{suffix}.weight'] = \
                            torch.stack([model_params[f'model.layers.{l}.block_sparse_moe.experts.{expert}.{suffix}.weight'].detach()
                                        for expert in rank_experts])
            w3 = model_params[
                f'model.layers.{l}.block_sparse_moe.experts.w3.weight']
            w2 = model_params[
                f'model.layers.{l}.block_sparse_moe.experts.w2.weight']
            w1 = model_params[
                f'model.layers.{l}.block_sparse_moe.experts.w1.weight']
            if moe_config.tp_mode == moe_config.ParallelismMode.TENSOR_PARALLEL:
                w3 = split(w3, mapping.tp_size, mapping.tp_rank, dim=1)
                w2 = split(w2, mapping.tp_size, mapping.tp_rank, dim=2)
                w1 = split(w1, mapping.tp_size, mapping.tp_rank, dim=1)

            model_params[
                f'model.layers.{l}.block_sparse_moe.experts.w3w1.weight'] = torch.concat(
                    [w3, w1], dim=-2)

            model_params[
                f'model.layers.{l}.block_sparse_moe.experts.w2.weight'] = w2

            ## block_sparse_moe.experts.w2.weight
            moe_experts_w2_weights = get_weight(
                model_params, prefix + 'block_sparse_moe.experts.w2', dtype)
            weights.update(
                get_tllm_linear_weight(moe_experts_w2_weights,
                                       tllm_prex + 'mlp.proj.', None,
                                       use_weight_only,
                                       plugin_weight_only_quant_type, dtype,
                                       use_gemm_woq_plugin))
            ##block_sparse_moe.experts.w3w1.weight
            moe_experts_w3w1_weights = get_weight(
                model_params, prefix + 'block_sparse_moe.experts.w3w1', dtype)
            weights.update(
                get_tllm_linear_weight(moe_experts_w3w1_weights,
                                       tllm_prex + 'mlp.fc.', None,
                                       use_weight_only,
                                       plugin_weight_only_quant_type, dtype,
                                       use_gemm_woq_plugin))

            if config.residual_mlp:
                residual_mlp_gate_weights = get_weight(
                    model_params, prefix + 'residual_mlp.w3', dtype)
                if use_smooth_quant:
                    residual_mlp_gate_weights = residual_mlp_gate_weights.t()
                    int8_weights = generate_int8(
                        residual_mlp_gate_weights,
                        act_range.get(prefix + 'residual_mlp.w3'))
                    weights.update(
                        get_tllm_linear_sq_weight(
                            int8_weights,
                            tllm_prex + 'residual_mlp.gate.',
                            [1, config.hidden_size // mapping.tp_size],
                            mapping.tp_size,
                            is_qkv=False,
                            per_token=per_token,
                            per_channel=per_channel,
                            last_prefix=tllm_prex +
                            'post_layernorm.scale_to_int',
                            smoother_value=None,
                            smoother_shape=None,
                            rank=mapping.tp_rank,
                            cat_dim=-1))
                else:
                    split_v = split_matrix_tp(residual_mlp_gate_weights,
                                              mapping.tp_size,
                                              mapping.tp_rank,
                                              dim=0)
                    weights.update(
                        get_tllm_linear_weight(split_v,
                                               tllm_prex + 'residual_mlp.gate.',
                                               None, use_weight_only,
                                               plugin_weight_only_quant_type,
                                               dtype, use_gemm_woq_plugin))

                residual_mlp_fc_weight = get_weight(model_params,
                                                    prefix + 'residual_mlp.w1',
                                                    dtype)
                if use_smooth_quant:
                    residual_mlp_fc_weight = residual_mlp_fc_weight.t(
                    )  #verified
                    int8_weights = generate_int8(
                        residual_mlp_fc_weight,
                        act_range.get(prefix + 'residual_mlp.w1'))
                    weights.update(
                        get_tllm_linear_sq_weight(
                            int8_weights,
                            tllm_prex + 'residual_mlp.fc.',
                            [1, config.hidden_size // mapping.tp_size],
                            mapping.tp_size,
                            is_qkv=False,
                            per_token=per_token,
                            per_channel=per_channel,
                            last_prefix=tllm_prex +
                            'post_layernorm.scale_to_int',
                            smoother_value=None,
                            smoother_shape=None,
                            rank=mapping.tp_rank,
                            cat_dim=-1))
                else:
                    split_v = split_matrix_tp(residual_mlp_fc_weight,
                                              mapping.tp_size,
                                              mapping.tp_rank,
                                              dim=0)
                    weights.update(
                        get_tllm_linear_weight(split_v,
                                               tllm_prex + 'residual_mlp.fc.',
                                               None, use_weight_only,
                                               plugin_weight_only_quant_type,
                                               dtype, use_gemm_woq_plugin))

                residual_mlp_proj_weight = get_weight(
                    model_params, prefix + 'residual_mlp.w2', dtype)

                if use_smooth_quant:
                    residual_mlp_proj_weight = residual_mlp_proj_weight.t()
                    int8_weights = generate_int8(
                        residual_mlp_proj_weight,
                        act_range.get(prefix + 'residual_mlp.w2'))
                    weights.update(
                        get_tllm_linear_sq_weight(
                            int8_weights,
                            tllm_prex + 'residual_mlp.proj.',
                            [1, config.hidden_size],
                            mapping.tp_size,
                            is_qkv=False,
                            per_token=per_token,
                            per_channel=per_channel,
                            last_prefix=tllm_prex +
                            'residual_mlp.quantization_scaling_factor',
                            smoother_value=smoother[prefix + 'residual_mlp.w2'],
                            smoother_shape=[
                                1, config.hidden_size // mapping.tp_size
                            ],
                            rank=mapping.tp_rank,
                            cat_dim=0))
                else:
                    split_v = split_matrix_tp(residual_mlp_proj_weight,
                                              mapping.tp_size,
                                              mapping.tp_rank,
                                              dim=1)
                    weights.update(
                        get_tllm_linear_weight(split_v,
                                               tllm_prex + 'residual_mlp.proj.',
                                               None, use_weight_only,
                                               plugin_weight_only_quant_type,
                                               dtype, use_gemm_woq_plugin))

            moe_experts_gate_weights = get_weight(
                model_params, prefix + 'block_sparse_moe.gate', torch.float32)
            weights.update(
                get_tllm_linear_weight(
                    moe_experts_gate_weights,
                    tllm_prex + 'mlp.router.',
                    None,
                    False,  # Router should never be quantized
                    plugin_weight_only_quant_type,
                    dtype,
                    use_gemm_woq_plugin))
        else:
            mlp_gate_weight = get_weight(model_params, prefix + 'mlp.up_proj',
                                         dtype)
            split_v = split_matrix_tp(mlp_gate_weight,
                                      mapping.tp_size,
                                      mapping.tp_rank,
                                      dim=0)
            if use_smooth_quant:
                mlp_gate_weight = mlp_gate_weight.t()
                int8_weights = generate_int8(
                    mlp_gate_weight, act_range.get(prefix + 'mlp.up_proj'))

                weights.update(
                    get_tllm_linear_sq_weight(
                        int8_weights,
                        tllm_prex + 'mlp.gate.',
                        [1, config.intermediate_size // mapping.tp_size],
                        mapping.tp_size,
                        is_qkv=False,
                        per_token=per_token,
                        per_channel=per_channel,
                        last_prefix=tllm_prex + 'post_layernorm.scale_to_int',
                        smoother_value=None,
                        smoother_shape=None,
                        rank=mapping.tp_rank,
                        cat_dim=-1))
            else:
                weights.update(
                    get_tllm_linear_weight(split_v, tllm_prex + 'mlp.gate.',
                                           None, use_weight_only,
                                           plugin_weight_only_quant_type, dtype,
                                           use_gemm_woq_plugin))

            mlp_fc_weight = get_weight(model_params, prefix + 'mlp.gate_proj',
                                       dtype)
            split_v = split_matrix_tp(mlp_fc_weight,
                                      mapping.tp_size,
                                      mapping.tp_rank,
                                      dim=0)

            if use_smooth_quant:
                mlp_fc_weight = mlp_fc_weight.t()  #verified
                int8_weights = generate_int8(
                    mlp_fc_weight, act_range.get(prefix + 'mlp.gate_proj'))
                weights.update(
                    get_tllm_linear_sq_weight(
                        int8_weights,
                        tllm_prex + 'mlp.fc.',
                        [1, config.intermediate_size // mapping.tp_size],
                        mapping.tp_size,
                        is_qkv=False,
                        per_token=per_token,
                        per_channel=per_channel,
                        last_prefix=tllm_prex + 'post_layernorm.scale_to_int',
                        smoother_value=None,
                        smoother_shape=None,
                        rank=mapping.tp_rank,
                        cat_dim=-1))
            else:
                weights.update(
                    get_tllm_linear_weight(split_v, tllm_prex + 'mlp.fc.', None,
                                           use_weight_only,
                                           plugin_weight_only_quant_type, dtype,
                                           use_gemm_woq_plugin))

            mlp_proj_weight = get_weight(model_params, prefix + 'mlp.down_proj',
                                         dtype)
            split_v = split_matrix_tp(mlp_proj_weight,
                                      mapping.tp_size,
                                      mapping.tp_rank,
                                      dim=1)

            if use_smooth_quant:
                mlp_proj_weight = mlp_proj_weight.t()
                int8_weights = generate_int8(
                    mlp_proj_weight, act_range.get(prefix + 'mlp.down_proj'))
                weights.update(
                    get_tllm_linear_sq_weight(
                        int8_weights,
                        tllm_prex + 'mlp.proj.', [1, config.hidden_size],
                        mapping.tp_size,
                        is_qkv=False,
                        per_token=per_token,
                        per_channel=per_channel,
                        last_prefix=tllm_prex +
                        'mlp.quantization_scaling_factor',
                        smoother_value=smoother[prefix + 'mlp.down_proj'],
                        smoother_shape=[
                            1, config.intermediate_size // mapping.tp_size
                        ],
                        rank=mapping.tp_rank,
                        cat_dim=0))
            else:
                weights.update(
                    get_tllm_linear_weight(split_v, tllm_prex + 'mlp.proj.',
                                           None, use_weight_only,
                                           plugin_weight_only_quant_type, dtype,
                                           use_gemm_woq_plugin))

        # Layer norms do not use tensor parallelism
        input_ln_weight = get_weight(model_params, prefix + 'input_layernorm',
                                     dtype)
        weights[tllm_prex + 'input_layernorm.weight'] = input_ln_weight

        post_ln_weight = get_weight(model_params,
                                    prefix + 'post_attention_layernorm', dtype)
        weights[tllm_prex + 'post_layernorm.weight'] = post_ln_weight

        if config.residual_mlp:
            residual_ln_weight = get_weight(model_params,
                                            prefix + 'residual_layernorm',
                                            dtype)
            weights[tllm_prex +
                    'residual_layernorm.weight'] = residual_ln_weight

        cur_block_weights = [
            weight_name for weight_name in model_params
            if weight_name.find(prefix) != -1
        ]
        for weight_name in cur_block_weights:
            model_params[weight_name] = None

    for l in layers_range:
        convert_layer(l)
        release_gc()

    v = get_weight(model_params, 'model.embed_tokens', dtype)
    if hf_model.config.tie_word_embeddings:
        # lm_head.weight has the same weights as embedding
        if mapping.is_last_pp_rank():
            if config.vocab_size % mapping.tp_size != 0:
                # padding
                vocab_size_padded = pad_vocab_size(config.vocab_size,
                                                   mapping.tp_size)
                pad_width = vocab_size_padded - config.vocab_size

                v = torch.nn.functional.pad(v, (0, 0, 0, pad_width), 'constant',
                                            0)
            weights['lm_head.weight'] = split(v, mapping.tp_size,
                                              mapping.tp_rank)

    if config.use_parallel_embedding:
        v = split_matrix_tp(v,
                            mapping.tp_size,
                            mapping.tp_rank,
                            dim=config.embedding_sharding_dim)

    if mapping.is_first_pp_rank():
        weights['transformer.vocab_embedding.weight'] = v

    lm_head_weights = get_weight(model_params, 'lm_head', dtype)

    if mapping.is_last_pp_rank():
        if config.vocab_size % mapping.tp_size != 0:
            # padding
            vocab_size_padded = pad_vocab_size(config.vocab_size,
                                               mapping.tp_size)
            pad_width = vocab_size_padded - config.vocab_size

            lm_head_weights = torch.nn.functional.pad(lm_head_weights,
                                                      (0, 0, 0, pad_width),
                                                      'constant',
                                                      value=0)
        weights['lm_head.weight'] = split_matrix_tp(lm_head_weights,
                                                    mapping.tp_size,
                                                    mapping.tp_rank,
                                                    dim=0)
        ln_f_w = get_weight(model_params, 'model.norm', dtype)
        weights['transformer.ln_f.weight'] = ln_f_w

    tok = time.time()
    t = time.strftime('%H:%M:%S', time.gmtime(tok - tik))
    print(f'Weights loaded. Total time: {t}')
    return weights


def smooth_quant(model,
                 tokenizer,
                 dataset,
                 smoothquant: Optional[float] = None):
    assert model is not None
    act_range = {}
    llama_qkv_para = {}
    # smoother for inputs of self_attn.o_proj and mlp.down_proj
    llama_smoother = {}

    act_range = capture_activation_range(model, tokenizer, dataset)
    if smoothquant is not None:
        smooth_llama_model(model, act_range, smoothquant, llama_qkv_para,
                           llama_smoother)
    return act_range, llama_qkv_para, llama_smoother


def quantize(hf_model_dir: str,
             output_dir: str,
             config: LLaMAConfig,
             calib_dataset='cnn_dailymail'):
    '''
        Quantize the save the model as TRT-LLM checkpoint to output_dir
    '''
    #TODO: currently only smooth quant and kv cache quantization are supported, needs to support mode quant algorithm calling modelopt

    with open(os.path.join(output_dir, 'config.json'), 'w') as f:
        json.dump(config.to_dict(), f, indent=4)

    mapping = config.mapping
    assert mapping.rank == -1, "You shall call quantize only once in one rank, assert rank==-1 for precaution"
    quant_config = config.quantization

    use_smooth_quant = quant_config.use_plugin_sq
    int8_kv_cache = quant_config.kv_cache_quant_algo == QuantAlgo.INT8

    assert use_smooth_quant or int8_kv_cache, "Call from_hugging_face when there is no quantization"
    if use_smooth_quant:
        assert quant_config.smoothquant_val is not None, "A smooth value must be specified when using smooth quant"

    assert hf_model_dir is not None
    ## only load and call smooth quant routine once for all ranks
    hf_config = AutoConfig.from_pretrained(hf_model_dir, trust_remote_code=True)
    assert "llava" not in hf_config.model_type, "Smooth quant llava/vila is not supported yet"
    hf_model = AutoModelForCausalLM.from_pretrained(
        hf_model_dir,
        device_map='auto',
        torch_dtype='auto' if not use_smooth_quant else torch.float16,
        trust_remote_code=True)

    os.environ["TOKENIZERS_PARALLELISM"] = os.environ.get(
        "TOKENIZERS_PARALLELISM", "false")
    tokenizer = AutoTokenizer.from_pretrained(hf_model_dir,
                                              trust_remote_code=True,
                                              use_fast=False,
                                              padding_side='left')

    dataset = load_calib_dataset(calib_dataset)

    act_range, qkv_para, smoother = smooth_quant(hf_model, tokenizer, dataset,
                                                 quant_config.smoothquant_val)

    for rank in range(mapping.world_size):
        # To avoid changing the mapping arg in-place, also the given mapping from caller is rank agnostic, since quantize is called from only one rank
        config = copy.deepcopy(config)
        config.set_rank(rank)
        weights = load_weights_from_hf_model(
            hf_model,
            config=config,
            act_range=act_range,
            qkv_para=qkv_para,
            smoother=smoother,
        )
        safetensors.torch.save_file(
            weights, os.path.join(output_dir, f'rank{rank}.safetensors'))
        del weights


class QkvWeightHelper:
    """ A helper utility for loading QKV weights from sharded files. """

    def __init__(self, config: PretrainedConfig):
        self.hidden_size = config.hidden_size
        self.num_heads = config.num_attention_heads
        self.num_kv_heads = config.num_key_value_heads
        self.tp_size = config.mapping.tp_size
        self.tp_rank = config.mapping.tp_rank
        self.is_mha = self.num_heads == self.num_kv_heads
        self._qkv_weights = {}

    @staticmethod
    def is_qkv_weight(name):
        for k in ['q_proj', 'k_proj', 'v_proj']:
            if 'self_attn' in name and k in name:
                return True
        return False

    def add_weight(self, i: int, name: str, weight: torch.Tensor):
        if 'q_proj' in name:
            tag = 'q'
        elif 'k_proj' in name:
            tag = 'k'
        elif 'v_proj' in name:
            tag = 'v'
        else:
            raise ValueError(f'Got an unexpected parameter of name {name}')
        if i not in self._qkv_weights:
            self._qkv_weights[i] = {}
        self._qkv_weights[i][tag] = weight

    def is_qkv_prepared(self, layer_idx):
        if layer_idx not in self._qkv_weights:
            return False
        weights = self._qkv_weights[layer_idx]
        return 'q' in weights and 'k' in weights and 'v' in weights

    def split_qkv_weights(self, layer_idx):
        if not self.is_qkv_prepared(layer_idx):
            return None
        weights = self._qkv_weights.pop(layer_idx)  # to prevent memory leak.
        q, k, v = (torch.tensor(weights[t]) for t in ['q', 'k', 'v'])

        if not self.is_mha:
            head_size = self.hidden_size // self.num_heads
            if self.num_kv_heads < self.tp_size:
                # duplicate the KV heads up to tensor_parallel
                k = dup_kv_weight(k, self.num_kv_heads, self.tp_size)
                v = dup_kv_weight(v, self.num_kv_heads, self.tp_size)
            assert k.shape[0] % (self.tp_size * head_size) == 0
            assert v.shape[0] % (self.tp_size * head_size) == 0
            wq = split(q, self.tp_size, self.tp_rank)
            wk = split(k, self.tp_size, self.tp_rank)
            wv = split(v, self.tp_size, self.tp_rank)
            fused_qkv = torch.cat((wq, wk, wv), dim=0)
        else:
            qkv = torch.cat([q, k, v], dim=0)
            qkv = qkv.reshape(3, q.shape[0], q.shape[1])
            fused_qkv = split(qkv, self.tp_size, self.tp_rank, dim=1)
            fused_qkv = fused_qkv.reshape(3 * (q.shape[0] // self.tp_size),
                                          q.shape[1])
        return fused_qkv


def load_weights_from_hf_by_shard(model_dir: str, config: LLaMAConfig):
    '''Weights-only quantization is the only supported quantization recipe here.'''
    logger.info('Loading weights from HF LLaMA...')
    quant_algo = config.quantization.quant_algo
    use_weight_only = quant_algo in [QuantAlgo.W8A16, QuantAlgo.W4A16]
    if quant_algo == QuantAlgo.W8A16:
        plugin_weight_only_quant_type = torch.int8
    elif quant_algo == QuantAlgo.W4A16:
        plugin_weight_only_quant_type = torch.quint4x2
    else:
        plugin_weight_only_quant_type = None

    weights = {}
    tik = time.time()
    dtype = getattr(torch, config.dtype)

    mapping = config.mapping
    moe_config = config.moe
    assert not moe_config.has_moe(), "MoE does not support sharded load"

    from transformers import AutoConfig
    hf_config = AutoConfig.from_pretrained(model_dir)

    quant_mode = config.quant_mode
    if quant_mode.is_int8_weight_only():
        plugin_weight_only_quant_type = torch.int8
    elif quant_mode.is_int4_weight_only():
        plugin_weight_only_quant_type = torch.quint4x2
    else:
        plugin_weight_only_quant_type = None
    use_weight_only = quant_mode.is_weight_only()

    layers_range = mapping.pp_layers(config.num_hidden_layers)

    qkv_weight_helper = QkvWeightHelper(config)

    for model_file in iterate_shard_files(model_dir,
                                          rank=mapping.tp_rank,
                                          progress_bar=False):
        logger.debug(f'Loading file {str(model_file)}...')
        model_params = load_state_dict(model_file, dtype=dtype)
        for name, param in model_params.items():
            logger.debug(f'Converting weight {name}...')
            layer_idx = retrieved_layer_index_from_name(name)
            if layer_idx is None:
                layer = None
            else:
                if layer_idx not in layers_range:
                    continue
            tllm_prex = f'transformer.layers.{layer_idx}.'

            if 'model.embed_tokens.weight' in name:
                if hf_config.tie_word_embeddings:
                    # lm_head.weight has the same weights as embedding
                    if mapping.is_last_pp_rank():

                        if config.vocab_size % mapping.tp_size != 0:
                            # padding
                            vocab_size_padded = pad_vocab_size(
                                config.vocab_size, mapping.tp_size)
                            pad_width = vocab_size_padded - config.vocab_size
                            param = torch.from_numpy(
                                np.pad(param.detach().cpu().numpy(),
                                       ((0, pad_width), (0, 0)),
                                       'constant',
                                       constant_values=0))
                        weights['lm_head.weight'] = split(
                            param, mapping.tp_size, mapping.tp_rank)
                if config.use_parallel_embedding:
                    param = split(param, mapping.tp_size, mapping.tp_rank,
                                  config.embedding_sharding_dim)
                if mapping.is_first_pp_rank():
                    weights['transformer.vocab_embedding.weight'] = param
            elif 'model.norm.weight' in name:
                if mapping.is_last_pp_rank():
                    weights['transformer.ln_f.weight'] = param
            elif 'lm_head.weight' in name:
                if mapping.is_last_pp_rank():
                    if config.vocab_size % mapping.tp_size != 0:
                        # padding
                        vocab_size_padded = pad_vocab_size(
                            config.vocab_size, mapping.tp_size)
                        pad_width = vocab_size_padded - config.vocab_size
                        param = torch.from_numpy(
                            np.pad(param.detach().cpu().numpy(),
                                   ((0, pad_width), (0, 0)),
                                   'constant',
                                   constant_values=0))
                    weights['lm_head.weight'] = split(param, mapping.tp_size,
                                                      mapping.tp_rank)
            elif 'input_layernorm.weight' in name:
                weights[tllm_prex + 'input_layernorm.weight'] = param
            elif 'post_attention_layernorm.weight' in name:
                weights[tllm_prex + 'post_layernorm.weight'] = param
            elif qkv_weight_helper.is_qkv_weight(name):
                qkv_weight_helper.add_weight(layer_idx, name, param)
                if not qkv_weight_helper.is_qkv_prepared(layer_idx):
                    continue
                split_v = qkv_weight_helper.split_qkv_weights(layer_idx)
                if use_weight_only:
                    param = split_v.transpose()
                    processed_torch_weights, torch_weight_scales = \
                        torch.ops.trtllm.symmetric_quantize_last_axis_of_batched_matrix(
                            param, plugin_weight_only_quant_type)
                    weights[tllm_prex +
                            'attention.qkv.weight'] = processed_torch_weights
                    weights[
                        tllm_prex +
                        'attention.qkv.per_channel_scale'] = torch_weight_scales
                else:
                    weights[tllm_prex + 'attention.qkv.weight'] = split_v
            elif 'self_attn.o_proj.weight' in name:
                split_v = split(param, mapping.tp_size, mapping.tp_rank, dim=1)
                if use_weight_only:
                    processed_torch_weights, torch_weight_scales = \
                        torch.ops.trtllm.symmetric_quantize_last_axis_of_batched_matrix(
                            split_v.transpose(), plugin_weight_only_quant_type)
                    weights[tllm_prex +
                            'attention.dense.weight'] = processed_torch_weights
                    weights[
                        tllm_prex +
                        'attention.dense.per_channel_scale'] = torch_weight_scales
                else:
                    weights[tllm_prex + 'attention.dense.weight'] = split_v
            elif 'mlp.up_proj.weight' in name:
                split_v = split(param, mapping.tp_size, mapping.tp_rank, dim=0)
                if use_weight_only:
                    processed_torch_weights, torch_weight_scales = \
                        torch.ops.trtllm.symmetric_quantize_last_axis_of_batched_matrix(
                            split_v.transpose(), plugin_weight_only_quant_type)
                    weights[tllm_prex +
                            'mlp.gate.weight'] = processed_torch_weights
                    weights[tllm_prex +
                            'mlp.gate.per_channel_scale'] = torch_weight_scales
                else:
                    weights[tllm_prex + 'mlp.gate.weight'] = split_v
            elif 'mlp.down_proj.weight' in name:
                split_v = split(param, mapping.tp_size, mapping.tp_rank, dim=1)
                if use_weight_only:
                    processed_torch_weights, torch_weight_scales = \
                        torch.ops.trtllm.symmetric_quantize_last_axis_of_batched_matrix(
                            split_v.transpose(), plugin_weight_only_quant_type)
                    weights[tllm_prex +
                            'mlp.proj.weight'] = processed_torch_weights
                    weights[tllm_prex +
                            'mlp.proj.per_channel_scale'] = torch_weight_scales
                else:
                    weights[tllm_prex + 'mlp.proj.weight'] = split_v

            elif 'mlp.gate_proj.weight' in name:
                split_v = split(param, mapping.tp_size, mapping.tp_rank, dim=0)
                if use_weight_only:
                    processed_torch_weights, torch_weight_scales = \
                        torch.ops.trtllm.symmetric_quantize_last_axis_of_batched_matrix(
                            split_v.transpose(), plugin_weight_only_quant_type)
                    layer.mlp.fc.weight.value = processed_torch_weights
                    layer.mlp.fc.per_channel_scale.value = torch_weight_scales
                    weights[tllm_prex +
                            'mlp.fc.weight'] = processed_torch_weights
                    weights[tllm_prex +
                            'mlp.fc.per_channel_scale'] = torch_weight_scales
                else:
                    weights[tllm_prex + 'mlp.fc.weight'] = split_v

        del model_params
    tok = time.time()
    t = time.strftime('%H:%M:%S', time.gmtime(tok - tik))
    logger.info(f'Weights loaded. Total time: {t}')
    return weights


def load_weights_from_hf_safetensors(model_dir: str, config: LLaMAConfig):
    logger.info('Loading weights from Huggingface LLaMA safetensors...')
    tik = time.time()
    import json
    import os

    import safetensors
    weights = {}

    model_dir = model_dir if model_dir.endswith("/") else model_dir + "/"
    safetensors_map = {}
    try:
        with open(model_dir + "model.safetensors.index.json", 'r') as fr:
            sharding_map = json.load(fr)
        for k, v in sharding_map['weight_map'].items():
            safetensors_map[k] = int(v[6:11]) - 1
    except FileNotFoundError:
        pass
    shard_files = []
    for name in os.listdir(model_dir):
        if name.endswith(".safetensors"):
            shard_files.append(name)
    shard_files.sort()
    safetensors_ptrs = [
        safetensors.safe_open(model_dir + shard_file,
                              framework="pt",
                              device="cpu") for shard_file in shard_files
    ]

    mapping = config.mapping
    num_hidden_layers = config.num_hidden_layers
    vocab_size = config.vocab_size
    pad_vocab = vocab_size % mapping.tp_size != 0
    vocab_size_padded = pad_vocab_size(config.vocab_size, mapping.tp_size)
    dtype = config.dtype

    moe_config = config.moe

    model_prefix = "model."
    key_list = [
        "embed_tokens.weight",  # vocab_embedding
        "lm_head.weight",  # lm_head
        "norm.weight",  # ln_f
        "self_attn.",  # attention.qkv
        "_proj.weight",  # qkv suffix
        "self_attn.o_proj.weight",  # attention.dense
        "mlp.up_proj.weight",  # mlp.gate
        "mlp.down_proj.weight",  # mlp.proj
        "mlp.gate_proj.weight",  # mlp.fc
        "input_layernorm.weight",  # input_layernorm
        "post_attention_layernorm.weight",  # post_layernorm
    ]

    torch_dtype = str_dtype_to_torch(dtype)

    def load(key, tp_dim=-1, no_prefix=0):
        if not no_prefix:
            key = model_prefix + key
        ptr_idx = safetensors_map[key] if key in safetensors_map else 0

        if key not in safetensors_ptrs[ptr_idx].keys():
            return None

        if tp_dim == -1:
            res = safetensors_ptrs[ptr_idx].get_tensor(key)
        else:
            tensor_slice = safetensors_ptrs[ptr_idx].get_slice(key)
            tensor_shape = tensor_slice.get_shape()
            if len(tensor_shape) == 1:
                if tp_dim == 0:
                    slice_width = tensor_shape[0] // mapping.tp_size
                    res = tensor_slice[slice_width *
                                       mapping.tp_rank:slice_width *
                                       (mapping.tp_rank + 1)]
                else:
                    res = tensor_slice[:]
            else:
                if tensor_shape[tp_dim] % mapping.tp_size != 0:
                    logger.error(
                        "Current weight shape is invalid for mapping.tp_size=" +
                        str(mapping.tp_size))
                slice_width = tensor_shape[tp_dim] // mapping.tp_size
                if tp_dim == 0:
                    res = tensor_slice[slice_width *
                                       mapping.tp_rank:slice_width *
                                       (mapping.tp_rank + 1), :]
                elif tp_dim == 1:
                    res = tensor_slice[:, slice_width *
                                       mapping.tp_rank:slice_width *
                                       (mapping.tp_rank + 1)]
                else:
                    assert False, "Invalid TP dim"
        return res.to(torch_dtype).contiguous(
        ) if "block_sparse_moe.gate" not in key else res.to(torch.float32)

    def load_and_set(target, key, tp_dim=-1, no_prefix=0):
        res = load(key, tp_dim, no_prefix)
        weights[target] = res
        if "weight" in key:
            bias = load(key.replace("weight", "bias"), tp_dim, no_prefix)
            if bias is not None:
                weights[target.replace("weight", "bias")] = bias

    if mapping.is_first_pp_rank():
        weights['transformer.vocab_embedding.weight'] = load(
            key_list[0], config.embedding_sharding_dim
            if config.use_parallel_embedding else -1)  # vocab_embedding

    if mapping.is_last_pp_rank():
        v = load(key_list[1], -1, 1) if pad_vocab else load(key_list[1], 0,
                                                            1)  # lm_head
        if pad_vocab:
            v = torch.nn.functional.pad(
                v, (0, 0, 0, vocab_size_padded - vocab_size), 'constant', 0)
            v = split(v, mapping.tp_size, mapping.tp_rank)
        weights['lm_head.weight'] = v
        weights['transformer.ln_f.weight'] = load(key_list[2])  # ln_f

    layers_range = mapping.pp_layers(num_hidden_layers)
    for l in layers_range:
        layer_idx = l - layers_range[0]
        prefix = f'layers.{l}.'
        tllm_prex = f'transformer.layers.{layer_idx}'

        # Attention
        qkv_list = []
        for comp in ["q", "k", "v"]:
            weight_part = load(prefix + key_list[3] + comp + key_list[4], 0)
            qkv_list.append(weight_part)
            bias_part = load(
                (prefix + key_list[3] + comp + key_list[4]).replace(
                    "weight", "bias"), 0)
            if bias_part is not None:
                qkv_list.append(bias_part)
        if len(qkv_list) == 3:
            # No bias
            weights[f'{tllm_prex}.attention.qkv.weight'] = torch.cat(
                qkv_list, 0)
        else:
            weights[f'{tllm_prex}.attention.qkv.weight'] = torch.cat(
                qkv_list[::2], 0)
            weights[f'{tllm_prex}.attention.qkv.bias'] = torch.cat(
                qkv_list[1::2], 0)
        load_and_set(f'{tllm_prex}.attention.dense.weight',
                     prefix + key_list[5], 1)  # attention.dense

        # MLP
        if not moe_config.has_moe():
            load_and_set(f'{tllm_prex}.mlp.gate.weight', prefix + key_list[6],
                         0)  # mlp.gate
            load_and_set(f'{tllm_prex}.mlp.proj.weight', prefix + key_list[7],
                         1)  # mlp.proj
            load_and_set(f'{tllm_prex}.mlp.fc.weight', prefix + key_list[8],
                         0)  # mlp.fc

        else:
            weights[f'{tllm_prex}.mlp.router.weight'] = load(
                prefix + 'block_sparse_moe.gate.weight')
            rank_experts = list(range(moe_config.num_experts))
            if moe_config.tp_mode == moe_config.ParallelismMode.EXPERT_PARALLEL:
                rank_experts = mapping.ep_experts(moe_config.num_experts)

            expert_weight_list = []
            for suffix in range(3):
                tp_dim = -1
                if moe_config.tp_mode == moe_config.ParallelismMode.TENSOR_PARALLEL:
                    tp_dim = 1 if suffix == 1 else 0
                expert_weight_list.append(
                    torch.stack(
                        list(
                            load(
                                prefix +
                                f'block_sparse_moe.experts.{expert}.w{suffix + 1}.weight',
                                tp_dim=tp_dim) for expert in rank_experts)))

            w1 = expert_weight_list[0]
            w2 = expert_weight_list[1]
            w3 = expert_weight_list[2]

            weights[f'{tllm_prex}.mlp.fc.weight'] = \
                torch.concat([w3, w1], dim=-2).contiguous()
            weights[f'{tllm_prex}.mlp.proj.weight'] = w2.contiguous()

        load_and_set(f'{tllm_prex}.input_layernorm.weight',
                     prefix + key_list[9])  # input_layernorm
        load_and_set(f'{tllm_prex}.post_layernorm.weight',
                     prefix + key_list[10])  # post_layernorm

    tok = time.time()
    t = time.strftime('%H:%M:%S', time.gmtime(tok - tik))
    logger.info(f'Weights loaded. Total time: {t}')

    return weights


def load_weights_from_gptq(quant_ckpt_path: str, config: LLaMAConfig):
    logger.info('Loading weights from groupwise GPTQ LLaMA safetensors...')
    weights = {}
    tik = time.time()

    num_hidden_layers = config.num_hidden_layers
    vocab_size = config.vocab_size
    dtype = config.dtype
    mapping = config.mapping

    gptq_llama = safetensors.safe_open(quant_ckpt_path,
                                       framework="pt",
                                       device=0)
    gptq_prefix = "model."
    gptq_suffix_list = [".qweight", ".qzeros", ".scales"]
    gptq_key_list = [
        "embed_tokens.weight",  # vocab_embedding
        "lm_head.weight",  # lm_head
        "norm.weight",  # ln_f
        "self_attn.",  # attention.qkv
        "_proj",  # qkv suffix
        "self_attn.o_proj",  # attention.dense
        "mlp.up_proj",  # mlp.gate
        "mlp.down_proj",  # mlp.proj
        "mlp.gate_proj",  # mlp.fc
        "input_layernorm.weight",  # input_layernorm
        "post_attention_layernorm.weight",  # post_layernorm
    ]
    split_sym = "."

    packer = torch.ops.trtllm.pack_int8_tensor_to_packed_int4
    preprocessor = torch.ops.trtllm.preprocess_weights_for_mixed_gemm
    torch_dtype = str_dtype_to_torch(dtype)

    def load(key, no_prefix=0):
        if no_prefix:
            return gptq_llama.get_tensor(key)
        else:
            return gptq_llama.get_tensor(gptq_prefix + key)

    def torch_split(v, dim):
        if v.shape[dim] % mapping.tp_size != 0:
            logger.error(
                "Current weight shape is invalid for mapping.tp_size=" +
                str(mapping.tp_size))
            assert False, "Invalid TP size"
        return v.split(v.shape[dim] // mapping.tp_size,
                       dim=dim)[mapping.tp_rank]

    def unpack_int32_into_int8(w_packed):
        # Unpack inputs packed in int32/float32 into uint4 and store them in int8 format
        w_packed_int4x2 = w_packed.contiguous().view(torch.uint8)
        w_unpacked = torch.zeros(w_packed_int4x2.shape[0],
                                 w_packed_int4x2.shape[1] * 2,
                                 dtype=torch.int8)
        w_unpacked[:, ::2] = w_packed_int4x2 % 16
        w_unpacked[:, 1::2] = w_packed_int4x2 // 16
        return w_unpacked.contiguous()

    def process_and_assign_weight(v: List[torch.Tensor],
                                  tllm_prex: str,
                                  tp_dim: int = -1):
        if tp_dim == -1:
            qweight_int32, qzeros_int32, scales_fp16 = [
                item.cpu() for item in v
            ]
        else:
            qweight_int32, qzeros_int32, scales_fp16 = [
                torch_split(item, tp_dim).cpu() for item in v
            ]

        USE_UINT4_INPUT = 1  # Set to true if checkpoint store UINT4 weights
        USE_GPTQ_FOR_LLAMA = 1  # GPTQ-for-LLaMA added 1 to zeros

        qweight_unpacked_int8 = unpack_int32_into_int8(
            qweight_int32.T).T.contiguous() - 8
        qweight_interleaved = preprocessor(packer(qweight_unpacked_int8),
                                           torch.quint4x2,
                                           torch.float16).view(torch.float16)
        # zeros = zeros * scales
        qzeros_unpacked_int32 = unpack_int32_into_int8(qzeros_int32)
        if not USE_UINT4_INPUT:
            # Correcting UINT4 values back to INT4 order
            mask_negative = qzeros_unpacked_int32[qzeros_unpacked_int32 < 0]
            mask_positive = qzeros_unpacked_int32[qzeros_unpacked_int32 >= 0]
            qzeros_unpacked_int32 = qzeros_unpacked_int32 + 16 * mask_negative - 16 * mask_positive
        zeros_x_scales_fp16 = (-qzeros_unpacked_int32 + 8 * USE_UINT4_INPUT -
                               USE_GPTQ_FOR_LLAMA) * scales_fp16
        zeros_x_scales_fp16 = zeros_x_scales_fp16.half()

        results = {
            f'{tllm_prex}.weight': qweight_interleaved,
            f'{tllm_prex}.weights_scaling_factor': scales_fp16,
            f'{tllm_prex}.zero': zeros_x_scales_fp16,
        }
        return results

    # Load weights from GPTQ checkpoint into TRT-LLM module
    # 1. vocab_embedding
    v = load(gptq_key_list[0])
    if mapping.is_first_pp_rank():
        # tensorrt_llm_llama.vocab_embedding.weight.value = v.to(
        #     torch_dtype).cpu().numpy()
        weights['transformer.vocab_embedding.weight'] = v.to(torch_dtype)
    # 2. lm_head
    v = load(gptq_key_list[1], "no_prefix")
    if mapping.is_last_pp_rank():
        # tensorrt_llm_llama.lm_head.weight.value = torch_split(
        #     v, 0).to(torch_dtype).cpu().numpy()
        if vocab_size % mapping.tp_size != 0:
            # padding
            vocab_size_padded = pad_vocab_size(vocab_size, mapping.tp_size)
            pad_width = vocab_size_padded - vocab_size
            v = torch.from_numpy(
                np.pad(v.detach().cpu().numpy(), ((0, pad_width), (0, 0)),
                       'constant',
                       constant_values=0))
        weights['lm_head.weight'] = torch_split(v, 0).to(torch_dtype)

    # 3. ln_f
    v = load(gptq_key_list[2])
    if mapping.is_last_pp_rank():
        # tensorrt_llm_llama.ln_f.weight.value = v.to(torch_dtype).cpu().numpy()
        weights['transformer.ln_f.weight'] = v.to(torch_dtype)
    # 4. Weights inside each layer
    layers_range = mapping.pp_layers(num_hidden_layers)
    for l in layers_range:
        layer_idx = l - layers_range[0]
        prefix = "layers" + split_sym + str(layer_idx) + split_sym
        logger.info(f'Process weights in layer: {layer_idx}')
        # layer = tensorrt_llm_llama.layers[layer_idx]
        tllm_prex = f'transformer.layers.{l-layers_range[0]}'
        # 4.1 attention.qkv
        qkv_weight_list = []
        for suf in gptq_suffix_list:
            qkv_list = []
            for comp in ["q", "k", "v"]:
                comp_part = load(prefix + gptq_key_list[3] + comp +
                                 gptq_key_list[4] + suf)
                comp_part = torch_split(comp_part, 1)
                qkv_list.append(comp_part)
            qkv_weight_list.append(torch.cat(qkv_list, dim=1))

        # process_and_assign_weight(layer.attention.qkv, qkv_weight_list)
        weights.update(
            process_and_assign_weight(qkv_weight_list,
                                      f'{tllm_prex}.attention.qkv'))
        # 4.2 attention.dense
        v = [load(prefix + gptq_key_list[5] + suf) for suf in gptq_suffix_list]
        # process_and_assign_weight(layer.attention.dense, v, 0)
        weights.update(
            process_and_assign_weight(v,
                                      f'{tllm_prex}.attention.dense',
                                      tp_dim=0))
        # 4.3 mlp.gate
        v = [load(prefix + gptq_key_list[6] + suf) for suf in gptq_suffix_list]
        # process_and_assign_weight(layer.mlp.gate, v, 1)
        weights.update(
            process_and_assign_weight(v, f'{tllm_prex}.mlp.gate', tp_dim=1))
        # 4.4 mlp.proj
        v = [load(prefix + gptq_key_list[7] + suf) for suf in gptq_suffix_list]
        # process_and_assign_weight(layer.mlp.proj, v, 0)
        weights.update(
            process_and_assign_weight(v, f'{tllm_prex}.mlp.proj', tp_dim=0))
        # 4.5 mlp.fc
        v = [load(prefix + gptq_key_list[8] + suf) for suf in gptq_suffix_list]
        # process_and_assign_weight(layer.mlp.fc, v, 1)
        weights.update(
            process_and_assign_weight(v, f'{tllm_prex}.mlp.fc', tp_dim=1))
        # 4.6 input_layernorm
        v = load(prefix + gptq_key_list[9])
        # layer.input_layernorm.weight.value = v.to(torch_dtype).cpu().numpy()
        weights[f'{tllm_prex}.input_layernorm.weight'] = v.to(torch_dtype)

        # 4.7 post_layernorm
        v = load(prefix + gptq_key_list[10])
        # layer.post_layernorm.weight.value = v.to(torch_dtype).cpu().numpy()
        weights[f'{tllm_prex}.post_layernorm.weight'] = v.to(torch_dtype)

    tok = time.time()
    t = time.strftime('%H:%M:%S', time.gmtime(tok - tik))
    logger.info(f'Weights loaded. Total time: {t}')

    return weights


def load_weights_from_meta_ckpt(meta_ckpt_dir: str, config: LLaMAConfig):
    torch_dtype = str_dtype_to_torch(config.dtype)
    mapping = config.mapping
    weights = {}

    def gather_ckpts(ckpts):
        gathered = {}
        for k in ckpts[0]:
            d = 0
            if any([n in k for n in ["wo", "w2", "tok"]]):
                d = 1
            if "norm" in k or "rope" in k:  # no TP
                gathered[k] = ckpts[0][k].clone()
            else:
                gathered[k] = torch.cat([pt[k] for pt in ckpts], dim=d).clone()
        return gathered

    def split_ckpt(ckpt, ranks_per_ckpt, ckpt_rank):
        split_ckpt = {}
        for k, v in ckpt.items():
            d = 0
            if any(n in k for n in
                   ["wo", "feed_forward.w2", "tok", "feed_forward.gate"]):
                d = 1
            if "norm" in k or "rope" in k:  # no TP
                split_ckpt[k] = v.clone()
            elif config.num_key_value_heads < mapping.tp_size and any(
                    n in k for n in ["wk", "wv"]):
                assert mapping.tp_size % config.num_key_value_heads == 0
                # special case: we need to duplicate KV head
                tmp = dup_kv_weight(v, config.num_key_value_heads,
                                    mapping.tp_size)
                split_ckpt[k] = torch.split(tmp,
                                            tmp.shape[d] // ranks_per_ckpt,
                                            dim=d)[ckpt_rank].clone()
            else:
                split_ckpt[k] = torch.split(v,
                                            v.shape[d] // ranks_per_ckpt,
                                            dim=d)[ckpt_rank].clone()
        return split_ckpt

    def get_current_weights(num_ckpts):
        if num_ckpts > mapping.tp_size:
            # combine ckpts
            assert (num_ckpts % mapping.tp_size) == 0
            nf = num_ckpts // mapping.tp_size
            fs = nf * mapping.tp_rank
            file_ids = list(range(fs, fs + nf))
            ckpts = []
            for f in file_ids:
                ckpt = torch.load(Path(meta_ckpt_dir,
                                       f"consolidated.{f:02d}.pth"),
                                  map_location="cpu")
                ckpts.append(ckpt)
            return gather_ckpts(ckpts)
        elif num_ckpts < mapping.tp_size:
            # split ckpt
            assert (mapping.tp_size % num_ckpts) == 0
            ranks_per_ckpt = mapping.tp_size // num_ckpts
            ckpt_fid = mapping.tp_rank // ranks_per_ckpt
            ckpt_rank = mapping.tp_rank % ranks_per_ckpt
            nH_per_ckpt = config.num_attention_heads // num_ckpts
            assert (nH_per_ckpt % ranks_per_ckpt) == 0
            ckpt = torch.load(Path(meta_ckpt_dir,
                                   f"consolidated.{ckpt_fid:02d}.pth"),
                              map_location="cpu")
            return split_ckpt(ckpt, ranks_per_ckpt, ckpt_rank)

        # num_ckpts == tensor_parallel, 1:1 mapping from files to TP
        return torch.load(Path(meta_ckpt_dir,
                               f"consolidated.{mapping.tp_rank:02d}.pth"),
                          map_location="cpu")

    def permute(w, nH, d, dH):
        # due to MQA's wk, nH*dH != d could be true
        return w.view(nH, dH // 2, 2, d).transpose(1, 2).reshape(nH * dH, d)

    def extract_layer_idx(name):
        ss = name.split('.')
        for s in ss:
            if s.isdigit():
                return s
        return None

    if not hasattr(load_weights_from_meta_ckpt, "saved_embed"):
        load_weights_from_meta_ckpt.saved_embed = None

    def combine_embeddings(embeds, num_ckpts):
        if len(embeds) == 1:
            return embeds[0]
        assert [
            embeds[i].shape == embeds[i + 1].shape
            for i in range(len(embeds) - 1)
        ]
        if embeds[0].shape[0] == config.vocab_size // num_ckpts:
            merge_dim = 0
        elif embeds[0].shape[1] == config.hidden_size // num_ckpts:
            merge_dim = 1
        else:
            logger.error("Unable to infer embedding split dimension")
            assert False, "Unable to infer embedding split dimension"
        return torch.cat(embeds, dim=merge_dim)

    def gather_embedding(cur_embed, name: str, num_ckpts):
        if mapping.tp_size == 1:
            # even if num_ckpts > 1, get_current_weights will already have it gathered
            return cur_embed
        if load_weights_from_meta_ckpt.saved_embed is None:
            embeds = [None] * num_ckpts
            for i in range(num_ckpts):
                ckpt = torch.load(Path(meta_ckpt_dir,
                                       f"consolidated.{i:02d}.pth"),
                                  map_location="cpu")
                embeds[i] = ckpt[name]
            embed = combine_embeddings(embeds, num_ckpts).to(torch_dtype)
            load_weights_from_meta_ckpt.saved_embed = embed

        return load_weights_from_meta_ckpt.saved_embed

    logger.info('Loading weights from Meta LLaMA checkpoints ...')
    tik = time.time()

    num_kv_heads = config.num_key_value_heads
    mha_mode = (num_kv_heads == config.num_attention_heads)

    ckpts = list(Path(meta_ckpt_dir).glob("consolidated.*.pth"))
    num_ckpts = len(ckpts)
    # llama/llama2 doesn't have MQA. So, simplifying loader logic by not worrying about it.
    assert num_kv_heads > 1 or num_kv_heads >= num_ckpts, \
        f"We don't know how the {num_kv_heads} KV heads are distributed among {num_ckpts} checkpoints."

    head_size = config.hidden_size // config.num_attention_heads
    ckpt = get_current_weights(num_ckpts)
    layers_range = mapping.pp_layers(config.num_hidden_layers)

    for l in layers_range:
        prefix = f'layers.{l}.attention.'
        q_weight = permute(ckpt[prefix + 'wq.weight'].clone(),
                           nH=(config.num_attention_heads // mapping.tp_size),
                           d=config.hidden_size,
                           dH=head_size)
        if num_kv_heads < mapping.tp_size and num_ckpts >= mapping.tp_size:
            assert mapping.tp_size % num_kv_heads == 0
            assert False, "Not supported yet"
        k_weight = permute(ckpt[prefix + 'wk.weight'].clone(),
                           nH=((num_kv_heads + mapping.tp_size - 1) //
                               mapping.tp_size),
                           d=config.hidden_size,
                           dH=head_size)
        v_weight = ckpt[prefix + 'wv.weight'].clone()

        qkv_weight = torch.cat([q_weight, k_weight, v_weight], dim=0)
        ckpt[prefix + 'qkv.weight'] = qkv_weight

    for k, v in ckpt.items():
        dtype = torch_dtype if 'feed_forward.gate' not in k else torch.float32

        v = v.to(dtype)
        if "tok_embeddings" in k:
            if not config.use_parallel_embedding:
                v = gather_embedding(v, k, num_ckpts)
            elif config.embedding_sharding_dim == 0:
                # this needs a gather and then resplit along different dims
                v = gather_embedding(v, k, num_ckpts)
                v = split(v, mapping.tp_size, mapping.tp_rank, 0)
            if mapping.is_first_pp_rank():
                weights['transformer.vocab_embedding.weight'] = v
        elif "output" in k:
            if mapping.is_last_pp_rank():
                if config.vocab_size % mapping.tp_size != 0:
                    # padding
                    vocab_size_padded = pad_vocab_size(config.vocab_size,
                                                       mapping.tp_size)
                    pad_width = vocab_size_padded - config.vocab_size
                    v = torch.from_numpy(
                        np.pad(v.detach().cpu().numpy(),
                               ((0, pad_width), (0, 0)),
                               'constant',
                               constant_values=0))
                weights['lm_head.weight'] = v
        elif k == "norm.weight":
            if mapping.is_last_pp_rank():
                weights['transformer.ln_f.weight'] = v
        else:
            # layer specific weights
            layer_idx = extract_layer_idx(k)

            if layer_idx is None or int(layer_idx) not in layers_range:
                continue
            idx = int(layer_idx) - layers_range[0]
            tllm_prex = f'transformer.layers.{idx}.'

            if 'attention_norm.weight' in k:
                weights[tllm_prex + 'input_layernorm.weight'] = v
            elif 'ffn_norm.weight' in k:
                weights[tllm_prex + 'post_layernorm.weight'] = v
            elif 'feed_forward.w3.weight' in k:
                weights[tllm_prex + 'mlp.gate.weight'] = v
            elif 'feed_forward.w2.weight' in k:
                weights[tllm_prex + 'mlp.proj.weight'] = v
            elif 'feed_forward.w1.weight' in k:
                weights[tllm_prex + 'mlp.fc.weight'] = v
            elif 'attention.wo.weight' in k:
                weights[tllm_prex + 'attention.dense.weight'] = v
            elif 'attention.qkv.weight' in k:
                weights[tllm_prex + 'attention.qkv.weight'] = v
            elif 'feed_forward.gate' in k:
                weights[tllm_prex + 'mlp.router.weight'] = v

    tok = time.time()
    t = time.strftime('%H:%M:%S', time.gmtime(tok - tik))
    logger.info(f'Weights loaded. Total time: {t}')
    return weights
